Propulsion of ships.



H. A. MAVOR.

PROPULSION 0P SHIPS. APPLICATION FILED SEPT. 20, 1508.

Patented Feb. 14, 1911.

' 1 SHEETS-SHEET 1.

H. A. MAVOR.

PROPULSION OF sms.

' APPLICATION I'ILED SEPT. 20, 1909.

983,917. Patented Feb. 14,1911.

4 SHEETS-SEEET 2.

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PROPULSION 0F SHIPS.

APPLICATION FILED SEPT. 20, 1909.

4 SHEETS-SHEET 3.

Patented Feb. 14,1911.

H A. MAVOIL- PROPULSION OP SHIPS.

APPLICATION TILED SEPT. 20, 1909. v

Patented Feb. 14, 1911.

4 SHEETS-SHEET 4.

UNITED STATES PATENT OFFICE.

HENRY ALEXANDER MAVOR, OF GLASGOW, SCOTLAND.

PROPULSION or sun's.

Application filed September 20, 1909. Serial No. 518,559.

T 0 all whom it may concern:

:Be it known that I, HENRY ALEXANDER 'MAvon, a subject of the King ofGreat Britain and Ireland, residing at Glasgow, Scotland, have inventedImprovements in or Relating to .the Propulsion of Ships, of which thefollowing is a specification.

This invention relates to the propulsion of ships and more particularlywar vessels which are to be capable of running at high speeds althoughalso frequently only performing long runs at low or reduced speeds. Asis well known, the power increase is not proportional to the speed sothat roughly speaking the power required to propel a given vessel athalf speed is only approximately about one eighth of the power requiredfor full speed.

The ob'ect of the present invention is to fit a vessel with a completepower equip-' ment which will fulfil the requirements of the variousservices to which it may be put,

in an economical manner, and the cost and weight of which will bereduced in comparison with the equipments at presentcmploycd. For thispurpose there is installed in the vessel, a main plant of any ordinarycharacter without intermediary electric transmission and of a power lessthan that required to propel the vessel at full speed, with which iscombined a supplementary ,electrical equipment of a special character.of a power appropriate for propelllng the vessel at a low or reducedspeed and capable also of being utilized in conjunction With the mainplant to drive the vessel at fullspeed.

The invention may be carried into effect in various ways For example,taking a cruiser requiring 18000 H. P. for a speed of 24 knots and whichmay be required to cruise for more or less protracted periods at 16knots, the main power plant may have a capacity sufiicient to produceabout 12.000 H. P. and the supplementary electric plant be designed tosupply about 6,000 H. P.

Conveniently, the main power plant may comprise one or more marineturbines supplied with steam from a generator or generators which is orare fired with oil fuels this being an arrangement which will enable 'anoil engine, supplied from the same fuel source, to be used for thesupplementary electric power plant. Obviously however the electricgenerator or generators of the supplementary electric plant might bedriven by turbines supplied with steam from the main boilers or fromindependent boilers; or a gas engine or engines might be employed todrive the said electric generator or generators.

The motor or motors of the supplementary electric plant comprising oneor more electric generators may conveniently be of the multiphase typedescribed in the specification of my for1ner Patent No. 912144 wherespeed variation is obtained with the aid of a multiphase controllingmotor. In other cases; there may be used in combination with a pluralityof collectively driven alternators having different periodicities, aplurality of'motors corresponding, or not, in number with thealternators and each possessed of a different number of poles to witheach appropriate alternator of the corresponding number of alternators,or with each of some of a non-corresponding number of alternato1's. thesame speed of rotation will be produced, this being an arrangementwl1iclr enables the capacity of --the generator of higest periodicity tobe reduced, all in the manner described in the specification of a formerBritish Patent No. 11183 of 1907.

By employing alternating current motors according to either of the twolast described patents, speed variations can be obtained depending uponthe characteristics of such motors but these speeds are capable offurther variation by employing means such as is described in thespecification of British Patent No. 28040 of 1.007, wherein the electricenergy is supplied to the motor or motors intermittcntly,or with a moreor less intermittent effect. so that the work to be done is accomplishedwith full power at intervals in contradistinction to continuously withlower power. In'this way the electric motor or motors may bemounted-upon the turbine or other motor driven shaft of the .7 mainpower equipment and its or their-speed adjusted to: the speed at whichit is desired to run the ship, the auxiliary electrically produced powerbeing thus added to the main (normallv produced) power at therequired'speed of rotation, or the said supplementary electric plantbeing used alone while cruising at low or reduced speeds and the turbineor other engine of the main power equipmentarranged to be disconl nectedat this time from the shaft which it the others so that when severallyconnected ispdapted to drive, or else in the 'case of The supplementaryelectric plant may, in

some cases, embody motors, for operation of auxiliaries on board thevessel, equal or approximately equal in power to the power of the motor;or motors used in propelling the vessel at reduced speed and adapted tobe used alternatively with such propelling motor or motors,substantially as described in former British specification No.'12386 of1907. v

The control of the motors may be effected by means such as is set forthin the, specification of my application for Patent No. 510,285 datedSeptember Mb-i909 wherein provision is made against the opening of thecircuit of the motor or motors at a switch for effecting change ofrunning conditions before the value of the current being suppliedthereto is reduced to a safe point.

In the accompanying illustrative drawings Figures 1, 2,3 and 4 arediagrammatic plans each showing a portion of a ship intended torepresent a 2i knot 18000 horse power cruisen provided with a motorequipment according to the present invention, the several figuresshowing various arrangements of power plants.

Referring .to Fig. l which is intended to represent a 2st knot 18000.horse power cruiser, a is a turbo-electric gei-ierator hav ing twopoles'and running at 7&0 revolutions per minute devcloping6000 H. P.,and I) is an electric motor developing 6000 H. P. mounted on the centralshaft 0 and energized by the generator (I. The wing shafts d are drivendirectly by the high and low pressure systei'ns c and 7' respectively ofan ordinary marine steam turbinedeveloping 0000 11.1.

in each element. The wing shafts d are furtheiprovlded, for alternativeapplication,

with electric motors g, each' developing 2000 H. P. at 370revolutionsper minute.

All three electric motors are of the type described in thespecification'of my said former Patent No. 912144, the main elementshaving six poles and a synchronous speed of about 246 revolutions perminute, while the controllin elements (hereinafter called the spinnerelements) have twelve poles and a synchronous speed of 123 revolutionsper minute, so that by subtracting, dispensing with or addingsuchspeeds. the main motor elements can be used to give respectivelyspeeds of 123, 246 and 370 revolutions supplied to the electric motor inthe manner described in the said former British specification No. 28040of 1907. At 10:} knots the turbines e, f are thrown out of action bybeing uncoupled from their shafts, or remaining coupled and runningvac-no. The motors 5 would then be supplied with um rent, the spinnersof the motors 71 9 being held stationary and the turbine of the gen--.erator a run at about four per cent. above its normal full speed and atapproximately its full load. The electric motors would run at anincrease of about four per cent. on their normal intermediate speed of246 revolutions per minute and at this speed the mo- .tors 7) and gnmst. develop 2000 H. P. each.

The turbine of the generator a can be slowed down without material lossof coonomy to twenty per cent. below its normal full speed so that thesaid generator can run economically at 600 revolutions per minute andthe electric motors at 200 revo-' lutions per minute. This speed ofrevolution corresponds to about thirteen knots. A further reduction ofspeed of the generator turbine,with a'slight loss of economy, would inthe same manner reduce the speed to twelve knots, while for lower speedsthe spinners would be brought into use in the reversedirection. k InFig. 2, the three shafts 0,-1Z are driven by a normal steam turbineequipment, comprising high pressure, intermediate and low pressuresystems It, 2', j, of about 5000 H. P. each. The electricequipmentconsists of a turbine generator 0- of 3000 H. P. at say 600 to740 revoluti ms per minute and of a 1000 'II. P. motor 7;, with spinner,oh each shaft. This arrangement provides for no intermet'liate speedsbetwen 24: knots and 13 knots except by reduction in turbine speed orelectric current interruption as already hereinbefore referred to. At 13knots the spinners of the electric motors are stopped and the motors runat 200 revolutions per minute. the generator turbine a being reduced tothe corresponding speed of 600 revolutions per minute, at which speed itis designed to give its full 3000 H. P. At 12 knots and at a slowerspeed, the conditions arethe same as described with reference to Whereit is desired to drive the auxiliaries of the ship electrically, anarrangement such as is shown in Fig. 3 may be adopted in which there isprovided a turbo generator m of 100) H. P. additional to the plan 1v essupplied with power from the main electric" 1O generator a, or at slowerspeeds by the electric'generator m, or its subdivisions, nor- Y mally-used for operating the, auxiliaries. The equipment-provides at fullspeed 18000 H. P. with the necessary additional power 15 forauxiliaries; at 13 knots 3000 H. I. in-

cluding if necessary the auxiliaries: and at 8 knots 1000 H. P.including the auxiliaries. {As already explained, speed change of themotors can secured in the manner described in the said former Britishspecification Np. 11183 of 1907. to exemplify which Fig. 4 has beenadded. In this example, the totalpower is 18,500 H. I..'the wing shaftsdbeing each driven by a 6000 H. I. turbine i or j-and theturl'io-generator being dividedinto three nnits w; 0, 7) whereof n and7) are of 2000 Th1. oar-b while 0 is of 2500 H. l.-'lhe motors on thewin; shafts are of 800 H. l. \vhilethe center shaft is provided withthree motors q. r, 8 each of 2000 H. 1.. but the motor 1; having 8 poleswhereas the motors r, a have each four poles. These motors are of theordinary squirrel cage type without spinners. Twp, nainel 11. 7), of thethree generators n, 0, p are two pole machines and the third 0 is a-fourpole machine. At full speed all three generators are used togetherttosupply current to the motors r r and s on the center shaft. running at370 revolutions per .minute. At half speed the generator 0 is alone usedto supply the motors on the wing shafts and to drive the eight polemotor q on the center shaft giving about '45 the same power. peedsintermci liatc of those capable of being; attained by the methoddescribed in the said former British specification No. 11183 of 1907 areobtained by throttling of steam. or interruption of current. as alreadyhereinbefom referred to. Obviously the turbo-generatorv plant and motorsof Figs. 2 and 3 may bc/modified to enable speed change to be secured asjust described.

\Vbat I claim is: 1. For the propulsion of a ship, the combination witha main theri'no mechanical plant of a supplementary alternating currentelectric plant capable of being used 60. either alone or in conjunctionwith the main plant. at will, for driving the ship at ditl'erent speedsand comprising an alternating.

current d rivii|; equipment. capable of being I run at ditl'er entspeeds. 2. For the propulsion of a ship, the cointric plant capable ofbeing used either alone or in conjunction-with the main plant, at

will, for driving the ship at different speeds and comprising amultiphase driving equi ment capable of being run at different spee s.

3. For the propulsion of a ship,a power equipmentcomprising a. mainplant-of a power less than that required to propel the ship at fullspeed and a supplementary alternating current electric equipment of apower appropriate for propelling the vessel at a low orreduced speed andcapable of being utilized in conjunction with the main plant to drivethe ship at full speed, said'electricequipment comprising electricdriving means having a characteristic that will admit of such equipmentbeing run at different speeds.

4. A power equipment for a'ship, comprising'a turbine plant foreffecting propul' sion alone'and a multiphase electric plant adapted tobe used alone for propulsion at a low speed or to'be used jointly withthe turbine plant to procure "propulsion" at full speed, said electricplant comprising one or more multiphase electric motors. having .a

characteristic that will admit of their being driven at definitedifferent speeds.

A power equipment fora ship, comprising a plurality of propeller shafts,turbines driving certain of. such shafts, multiphase electric motors nthe several shafts,

and turbo driven multiphase electric generating plant adapted to supplycurrent to such motors.

6. A power equipment for a ship, com

prising a plurality of propeller shafts,'turbinesdriving certain of suchshafts, multiphase' electric motorson the several shafts and asub-divided turbo-driven multiphase generator .plant adapted to supplycurrent to such motors.

7. A power equipment for a ship, comprising a plurahtypf propellershafts, turbiues driving certain of such shafts, amultiphase electriccurrent motor on each of such turbine driven shafts, a plurality ofmultiphase electric motors on another of, said shafts and a multiphaseelectric current generator plant divided into units for supplyi-rs ingmultiphase current to the various motors in different ways.

8. For the propulsion of a shlp, the combination with a main thermomechanical quired to propel'the vessel at full speed, of a.supplementary electric vequipment comprising multiphase inductiondriving motors, multiphase controlling motors therefor and amnltiphase'altei-nat'e current generator for supplying energy tothedriving and controlling motors, the said electric'equipment beingarranged to be used aloncfor propelling the vessel at a low or reducedspeed and .120 driving plant ofa power less than that re- I capable ofbeing utilized in conjunction with prisi the 'thermo -mechanical drivingdrive the'ship at full speed.

9. A power equipment for a ship, comprising a turbine propulsion plantand an electric propulsion plant comprisin multiplant to phase inductiondriving motors, mu tiphase controlling motors-for the driving motors andagenerator for supplying multiphase current to all the motorsindiiferent ways 'to efiect speed change, said turbine propulsion plantbeing arranged to be used alternatively or corqointly with the electricpro-' 'to the several motors and s inner s? in different ways to effectspeed c ange:

115A power equipment fora ship, comprising in combination with aplurality of propeller shafts, turbines' for driving certain of suchshafts, multi 'hase electric induction driving motors on t e saidturbine driven shafts each such driving motor beingcontrolled by' aspinner, and asub-divided turbo-generator plant adapted 'to supplymultiphase current to the motors and spinners in difi'erent ways, toefiect speed change.

12. A power equipment for a ship, comprising in combination with alurality of propeller shafts, turbines for tain of such shafts,anelectric induction mo to'r on each of said turbine driven shafts and"each controlled by a spinner, a plurality iving oer.-

of electricinduction motors on another shaft, A

and an electric. generator plant divided into 'units'for supplyingcurrent to the various motor-sand spinners in different ways, to effectspeed change.

Signed at London, England this 9th day of Se tember. 1909. I Y z i-lENRYALEXANDER MAYOR. 4 Witnesses; I WILLIAIfPRINGL E,

ARTHUR A. FISHER.

